1999 F360 Modena

I have found on Cars.com a 1999 F360 Modena with 19,000 miles in Bradenton, Florida and the asking price is $115,000. They say they will lease it for a minimum of 3 months 500 miles a month for $2500 a month. I am thinking of saying to them that I will lease it for 3 months and if I fall in love I will buy it but only if the three months lease payment will be applied to the selling price AND if they will perform the 30,000 mile service on their dime.

Here are my questions: does this make sense to you guys and what is this car gonna be worth when it hits 30,000 miles? Thanks in advance for your advice.